My wife and I have spent many happy days collecting fossils on the Yorkshire Coast between Staithes (NZ783189) in the North and Scarborough (TA041893) in the South. As a result of our collecting I have put together this page to help people who find fossils in this area to understand what they are and what they once were.

The rocks in this area cover a period from Lower Jurassic (approx 190 million years old) to Middle Jurassic (approx 150 million years old). The older rocks are generally towards the North of this area and the younger rocks to the South. During this time period Britain was much closer to the equator and in the Lower Jurassic the Yorkshire Coast was under the surface of a warm tropical sea. As time progressed, as the result of earth movements, the sea became shallower and about 160 million years ago the area was more like a river delta with swamps and lagoons. Some of the inhabitants of this area during this time have been preserved as the fossils we find on the beach and in the cliffs.

What is a fossil?

In its simplest form - something dies, usually in water - it slowly gets covered with sand, mud or silt as the soft parts decompose and leave a cavity - over millions of years the cavity becomes filled with mineral substances which form a cast of the original creature or plant and, because of the great pressure of the overlying covering, the cast usually becomes deformed.

Fossilisation Process

There are a great number of variations to this theme, the creature or plant may die on land and be covered by sand from a high tide, it may be washed into a river or it may be covered over by volcanic dust. In some cases the whole thing will not decompose and the fossil will still contain some of the original item, for example shells, resins, oils and carbonised remains.

Yorkshire Coast Fossils

Scale - The black squares in each picture are 1cm. each.
The figures in brackets are UK Ordnance Survey Map References.

Ammonites

Ammonite - Dactylioceras sp. The most popular fossil from the Yorkshire Coast is the ammonite. Resembling a coiled snake, called 'snakestones' locally ammonites can be found along the whole length of coast fromReconstructed Ammonite Staithes to Scarborough. When alive an ammonite resembled the modern day pearly nautilus, rather like a squid in a shell. The creature only lived in approximately a third of the outer portion of the shell, the rest of the shell being made up of gas filled chambers that acted as bouyancy aids to enable the ammonite to swim without sinking.

In the Whitby (NZ900103) area ammonites are generally preserved in three ways, they will either be found squashed very flat on the surface of shale(1), preserved more or less intact inside an ironstone nodule (2) or preserved in mudstone, usually with the outer whorl intact but the centre squashed (3).

1Ammonite - Harpoceras sp. from shale2Ammonite - Dactylioceras sp. in ironstone nodule3Ammonite - Harpoceras sp. from mudstone

Local legend says that the ammonites were formed when the Abbess ofAmmonite - Hildoceras sp. in nodule Whitby (later St. Hilda), drove a plague of snakes over the cliff at Whitby. The species of ammonite pictured on the right was named Hildoceras in honour of this mythical feat.

A WORD OF WARNING - although collecting fossils from the shale and mudstone is reasonably safe, take great care if you are trying to break open the ironstone nodules with a hammer, very sharp flakes of ironstone will shoot off at all angles and may blind you if you are hit in the eye. Also please beware of rocks falling from the unstable cliffs and watch the tides (it is very easy to get cut off in some places).
 

Belemnites

Belemnite 12cm long.Belemnite 8.5cm long.

The local name for these fossils is 'Devils Thunderbolts' and they do resemble bullets. The nearest modern equivalent for the part most commonly found is a cuttlefish bone (often found in Budgie's cages).Reconstructed Belemnite As with ammonites, the belemnite was a squid like creature but instead of having the ammonite's external shell the hard structure of a belemnite was on the inside. This internal shell is known as the guard.

Belemnites vary in size and shape, unusual long thin ones (Cuspiteuthis tubularis) can be found on the surface of the shale near to Black Nab in Saltwick Bay (NZ922108).

Cuspiteuthis tubularis 27.5cm longPhragmocones. The extension to the guard in a belemnite is known as the phragmocone. As the phragmocone was more delicate than the guard they are more difficult to find as they are unlikely to have been preserved intact. Occasionally they will be preserved inside an ironstone nodule and more rarely in shale. The guard with phragmocone attached in the picture below was found at Whitby (NZ905114) and the nodule is from Saltwick Bay (NZ915109).

Belemnite with phragmoconeBelemnite phragmocone in nodule
 

Dinosaur Footprints

Dinosaur Footprint Although not a true fossil and described as a 'trace fossil', it can be very exciting to find evidence that dinosaurs once roamed this area. Approximately 160 million years ago when the area around Whitby was a huge river delta there were large mudflats which were roamed by dinosaurs. Dinosaurs walking in the mud of course left footprints. Some of the mud, with footprints, dried very hard in the tropical heat. As the result of a flash flood or very high tide some of the footprints became covered by sand. The sand and mud layer became further buried by more layers of sand, silt and mud and over time changed into sandstone and mudstone. The footprints we find nowadays are actually 3D sandstone casts of the original footprint.

The best place to look for dinosaur footprints is Burniston Bay near Scarborough (TA027935). Follow the steps down to the beach and then turn left, the large sandstone blocks at the base of the small cliff sometimes have three toed footprints on the surface. The footprint bed is the layer of sandstone about 3-4 metres up the cliff face from which these blocks have fallen. Although Burniston Bay is the easiest place to find the footprints, they can be found all along the coast from Scarborough to Whitby. The one in the picture was found at Saltwick Bay (NZ915109).
 

Plant Remains

Ginkgo huttoni, LeavesPtilophyllum pecten, LeavesPlant remains are quite common in the Whitby and Scarborough areas. Leaves are usually preserved as carbon impressions of the original leaf. Tree trunks and branches are sometimes preserved as flattened coal like bands, sometimes as mineralised casts and occasionally as Jet.

Raw Whitby Jet

Click here to visit my Jet pages

The Ginkgo leaves (left) are from the 'Scalby Plant Beds' at Scalby Ness (TA037912) just North of Scarborough. The Ptilophyllum (right) from the 'Whitby Plant Beds' (NZ910114) South of Whitby. The well preserved section of tree trunk (below) was found on the beach at Robin Hood's Bay (NZ954054).

Tree Trunk, side viewTree trunk, end view
 

Marine Reptiles

IchthyosaurPlesiosaur

Ichthyosaur VertebraeDuring the Jurassic period the seas in this part of the world were the home of ichthyosaurs and plesiosaurs. Both measured from 3 to 13 metres in length. The ichthyosaur resembled a dolphin in appearance and is thought to have been a fast and powerful swimmer. The ichthyosaur was the only marine reptile known to give birth to live young. The plesiosaur had a very long neck and used four paddle like fins for propulsion. In contrast to the ichthyosaur, the plesiosaur would leave the water to lay eggs on the land. It is thought that if the Loch Ness Monster exists it is probably a descendent of the plesiosaur. Both reptiles were air breathers and would have to surface regularly for air.

Ichthyosaur VertebraAlthough fossilised remains of reptiles are uncommon they can be found in this area. Vertebrae are the most common parts to be found, usually on the seashore, and look like discs with concave sides ranging from 1cm to 30cm in diameter. Complete skeletons are still occasionally found in the cliffs but are extremely difficult to remove intact.

The two smaller vertebrae pictured on the right are from Saltwick Bay and the single larger vertebra on the left was found on the beach between Saltwick bay and Whitby, unfortunately it is broken in half and the other part could not be found.
 

Bivalves

Jurassic Bivalve Gryphaea arcuata, Jurassic BivalveJurassic BivalveJurassic Oyster

Dacryomya ovum, Jurassic BivalveCockles, mussels and oysters are all bivalves. The only difference is that some of the shellfish you find on the Yorkshire Coast are 150 to 190 million years old (not the ones on the seafood stalls).

When shellfish died most of the shells became filled with mud or silt, this provided a solid 'core' for the shell as it became fossilised. As the shell was made of a substance similar to the fossilising minerals quite often parts of the shell remain intact and the original colours are visible.

The shell pictured to the right is called Dacryomya ovum (formerly Nuculana ovum) and is very common around Whitby (NZ904115), beds of hundreds of the fossilised shells can be found in the cliff face and large numbers loose on the seashore.
 

Crinoids

Reconstructed CrinoidPentacrinites fossilis, OssicleAmongst the shingle on the beach you may find very small fossils which resemble starfish. These are not starfish, they are part of a crinoid, a creature which is related to the starfish. A crinoid can be described as rather like a starfish on a stem. The stem would be made up of hundreds of these flat star shaped plates, called ossicles, stacked one on top of the other. At the top of the stem would be the head (calyx) with 5 or more arms which were used to catch food and at the bottom of the stem a 'root' system to hold the creature down. Although crinoids look like plants and have the nickname 'sea lillies' they are not plants.

Pentacrinites fossilis, CalyxPictured on the right is what we think is a badly damaged calyx and arms assemblage of a Pentacrinites fossilis crinoid.This was found in Robin Hood's Bay.
 

 

Scaphopods

Scaphopod - Dentalium Reconstructed Scaphopod

Scaphopods are shellfish which first put in an appearance in Devonian times (417 to 354 Million Years Ago) and have hardly changed since. They can still be found in warmer climates and are known as 'tusk shells' because of their similarity in appearance to elephant's tusks.
In life a scaphopod lives buried in sand with just the thin end of the shell protruding into the water and the head end (called the foot) at the lower end. The picture on the right shows a scaphopod in life position.

The scaphopod pictured above, Dentalium Giganteum, was found in a loose block of siltstone at Robin Hoods Bay (NZ958059) although they are much more common on the east side of Staithes Harbour (NZ788190) where they can be seen as clusters of white lines on the surface of the rock platform.
 

Collecting

It can be fun collecting fossils but the area between Staithes and Scarborough can also be very dangerous. The cliffs are constantly losing pieces from small flakes of shale to massive boulders of sandstone and they fall downwards.It is a good idea to look up occasionally and see how near to the cliffs you are. If one of the larger pieces falls on your head you are DEAD! Most of our fossils and all of the 'best' ones (including the Dino Footprint) came from amongst the shingle, shale and rocks well away from the cliffs and did not have to be hammered out. Hammering and chiselling the cliff face can cause cliff falls and after a lot of effort you will most likely end up with a broken part of a fossil. Looking carefully around on the ground will most likely produce a lot better (possibly undamaged) specimen without the risk to life and limb.

Beware of the tides, some areas can get cut off up to 3 hours before high tide. Always check the tide tables and if you are new to the area then talk to the locals. Robin Hoods Bay can be particularly frightening, the shore is flatt(ish) and the tide suddenly starts to come in very fast. Once you are trapped by the tide climbing the cliffs is not an option. At best you may have to wait up to 6 hours for the tide to go down, at worst you will DROWN.

If you must hammer then ALWAYS wear protective goggles and particulary if you try to break open a ironstone nodule.When hammering or chiselling there is a good chance that thin sharp slivers of rock will break off and fly in all directions, please wear eye protection. I know they can be cumbersome and some people may think it is 'soft' to wear them but, I would sooner be 'soft' than BLIND.

OK... enough. If I haven't put you off collecting fossils in this area then please click on these links to take you to Mike Horne's excellent notes on GEOLOGICAL FIELDWORK and COLLECTION AND CURATION OF GEOLOGICAL MATERIALS. They will tell you how collecting is done by the experts and how it should be done by everybody.

That's it for now. If we find anything else interesting or you suggest anything we can add to this page we will update it as necessary.

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